Japanese Patent Laid-Open No. 2004-328631 discloses a technique that a number of apparatuses for processing information which generate images are connected to an apparatus for processing an image which prints images through a network so that the apparatuses for processing information share the single apparatus for processing an image.
Like the technique of the above document, it is a common practice to connect an apparatus (hereinafter called “image display apparatus”) for displaying an image with a number of apparatuses (hereinafter called “image transmitting apparatus”) that transmit an image to the image display apparatus over a network and to display images transmitted from the image transmitting apparatuses on the single image display apparatus. For example, a number of persons may attend a meeting with their own information processing apparatuses, such as a notebook PC and a mobile terminal, may connect the information processing apparatuses to a single projector by way of a network, and may make the projector display materials stored in their information processing apparatuses.